Two-phase alternating-current distribution.



H. S. RUSSELL 6v P. E. BERRY.

TWO PHASE ALTERNATING GURRENT DISTRIBUTION.

APPLICATION FILED MAY 6, 1907.

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HERBERT SIDNEY RUSSELL, OF HANWELL, AND FREDERICK EDMUND BERRY, OF WESTDRAYTON, ENGLAND.

TWO-PHASE ALTERNATING-CURRENT DISTRIBUTION.

Specification of Letters Patent.

Patented Dec. 8, 1908.

Application filed. May 6, 1907. Serial N 0. 372,015.

To all whom it may concern:

Be it known that we, HERBERT SIDNEY RUSSELL and FREDERICK EDMUND BERRY,both subjects of the King of Great Britain, residing, respectively, atFenbrook, Manor Court Road, Hanwell, in the county of Middlesex, and atNapoleon Villa, Vest Drayton, in said county, England, have jointlyinvented certain new and useful Improvements in Two-PhaseAlternating-Current Distribution, of which the following is aspecication.

This invention relates to two-phase systems of electrical distributionand in particular, although not exclusively, to the twophase three-wiresystem in which a common return is provided for the two circuits, or inwhich the two returns are connected to a common bus bar, and consists inan improved arrangement of booster transformers according to which,instead of boosting the differently phased circuits separately, theboosting of both circuits is effected by the same transformer.

In the accompanying drawings Figure l one arrangement of the boostertransformer windings according to the present invention, Fig. 2 being amodied arrangement thereof.

In both cases the booster or secondary winding a of the transformer isincluded in the common return conductor or bus bar b, a suitableregulating switch c being inserted if required to vary the number ofeffective turns or otherwise vary the voltage of the secondary.

In what would be the usual arrangement (Fig. l), there are two boostingor primary windings d', Z2 which are respectively connected between theseparate phase conductors e', e2 and the common return or4 bus bar b Incertain circumstances it may be desirable to effect a positive boost onone phase and a negative boost on the other, and in this case thearrangement ofv Fig. 2 is used, in which the transformer has a singleprimary winding d, connected across the separate phase conductors e',e2. It will be obvious that the boosted voltage may also be varied byvarying the effective turns of the primary windings and that thesecondary winding' may be arranged in inductive relation with the commonreturn instead of being included conductively therein.

Having thus described the nature of this invention and the best means weknow of carrying the same into practical effect, we claim z* l. In atwo-phase alternating current distribution system having a common returnconductor for both phases of the current, the method of boosting whichconsists in applying a boosting effort to the said return conductorwhich carries both phases of the current; substantially as described.

2. In a two-phase alternating current distribution, a boostertransformer having coils or windings arranged to boost both phases ofthe current simultaneously.

3. In two-phase alternating current distribution having a common returnconductor, a booster transformer having its boosted winding in thecommon return, substantially as described.

4. In two-phase alternating current distribution having a common returnconductor, a booster transformer having its boosted winding in thecommon return and its boosting or primary winding connected with theseparate phase conductors, substantially as described.

5. In two-phase alternating current distribution, a booster transformerhaving its boosted winding in the common return two boosting or primarywindings connected respectively between the separate phase conductorsand the common return, substantially as described.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing witnesses.

HERBERT SIDNEY RUSSELL. FREDERICK EDMUND BERRY.

Witnesses:

JOSEPH WILLARD, WALTER J. SKERTEN.

